Metallized disazo dyes



United States Patent METALLIZED DISAZO DYES Albert Webb Bauer and Ernest Cseudes, Wilmington,

Del., assignors to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Application June 29, 1956 Serial No. 594,705

7 Claims. (Cl. 260-148) This invention relates to novel metallized disazo dyes, suitable as direct dyes for cotton. It is an object of this invention to provide novel dyestuffs of the above type, which are useful as direct dyes for cellulosic fiber such as cotton and viscose rayon, and which produce on these fibers greenish blue to bluish grey shades of outstanding light fastness and wash fastness. Another object is to produce dyestuffs of the aforegoing character which will not lose their light fastness even if the dyed fiber is aftertreated with resinous agents as for the purpose of crease proofing or calendering. A further object is to produce dyestuffs of the aforegoing character which may be applied to mixtures of cotton and nylon without staining the latter. A still further object is to provide a process for producing the aforegoing dyestulfs in a state of high purity. Various additional objects and advantages of this invention will become apparent as the description proceeds.

It is known that direct dyestulfs for cotton may be obtained by coppering disazo dyes of the general formula OAIk OAlk OH wherein R -OH and R -OH represent the radicals of various naphthol and amino-naphthol sulfonic acids, while Alk is a lower alkyl radical (usually 1 to 2 C-atoms). The coppering is generally achieved by treating an alkaline aqueous solution of the disazo dye with an ammoniacal solution of a copper salt, for instance cuprammonium sulfate, in the presence of an excess of ammonia or of a water-soluble organic amine. In the process, the alkyl groups on the OAlk radicals as well as the H atoms of the OH radicals become eliminated and replaced by copper atoms, which are generally coordinated by auxiliary valencies to the N-atoms of the azo bridges. Moreover, one or more molecules of ammonia or of the organic amine employed generally becomes coordinated with each copper atom. Consequently, the metallized disazo compound has the general formula wherein R and R have the same meaning as above, while X represents a molecule of ammonia orof the coordinated amine.

As amines commonly employed hitherto for this purpose may be mentioned methylamine, ethylamine, piperidine, mono-, dior triethanolamine, morpholine and pyridine. i

We have now found that considerable improvement in light fastness of theresulting dye, accompanied often by} a diminished tendency to stain nylon fiber, is achieved by 2,842,536 Patented July 8, 1958 ice selecting, as basic nitrogenous agent in the coppering pro cedure, an amino-sugar of the general formula CH OH (CHOH) -CHgNHR wherein x is an integer not less than 3 and not greater than 4, while R is a member of the, group consisting of hydrogen, methyl, ethyl and betahydroxyethyl.

As practical illustrations of such amino-sugars may be mentioned glucamine, methyl glucamine, ethyl glucamine, betahydroxyethyl glucamine, methyl xylamine and methyl galactamine. In the discussion which follows, wherever methyl glucamine is named, it is meant to typify the entire group.

Particularly outstanding improvements in the above respects are obtained if at least one of the sulfonated naphthol radicals .R OH and R OH is the radical of an amino-naphthol disulfonic acid, for instance H-acid, N-ethyl H-acid or RR-acid.

For the purpose of making clearer the discussion which follows and the specific examples hereinbelow, the following table of names of coupling components is given: H acid8-amino-1-naphthol-3,6-disulfonic acid Gamma acid-7-amino-1-naphthol-3-sulfonic acid Chicago acid8-amino-Luaphthol-SJ-disulfonic acid Violet acid1-naphthol-3,6-disulfonic acid RR acid7-aminol-naphthol-3,6-disulfonic acid Epsilon acid1-naphthol-3,8-disulfonic acid R acid-Z-naphthol-3,6-disulfonic acid N-ethyl H acid8-ethylamino-1-naphthol-3,6-disulfonic acid K acid-S-amino-1-naphthol-3,5-disulfonic acid Schaeifers acid- -2-naphthol-6-sulfonic acid I acid-6-amino-1-naphthol-3-sulfonic acid L acid-l-naphthol-S-sulfonic acid Accordingly, our invention may be restated as comprising a groupof novel metallized disazo dyes of the general Formula 2 above, wherein X is an amino-sugar, R -O is the radical of an amino-naphthol disulfonic acid while 0-R is the radical of a naphthol-, aminonaphthol-, or aryl-methyl-pyrazolone monoor disulfonic acid, for instance, H-acid, N-ethyl H-acid, gamma acid, any other of the acids named in the above table, l-(mor p-sulfophenyl)-3-methyl-5-pyrazolone or 1-(6,8-disulfo-l-naphthyl)-3-methyl-5-pyrazolone.

Apart from the above features of coppering in the presence of methyl-glucamine and of selecting at least one of the members R and R as specified above, the

coppering procedure may proceed in ordinary manner.

The copper salt selected may be cupric sulfate, cupric nitrate, cupric chloride or cupric, acetate. Cupric hydroxide or freshly precipitated cupric oxide may also be employed. In each case, the copper compound is first converted into an aqueous cuprammonium solution in the product. The theory of this action is not entirely clear to us, but it may be that the excess of methylglucamine serves to solubilize impurities formed during the coupling, thereby aiding in their removal during the salting out of the final dye.

Without limiting our invention, the following examples are given to illustrate our preferred mode of operation. Parts mentioned are by weight.

2,842,536 3 4 EXAMPLE 1 and cotton or nylon and viscose rayon without staining the nylon fiber.

When the N-methyl glucamine used in the metalliza- P mole) of o-diallisidifle are slurried in tion step is replaced by 74 parts of glucamine or 86 200 Parts of Water andtetrazotized at to C in 5 parts of N-ethyl glucamine similar results are obtained.

Part 1.Preparati0n of the disazo dye usual manner With @mixmm of hydrochloric and 5111- Likewise, equivalent amounts of other polyhydroxy alifuric acid and sodium nitrite solution. The excess of phatic amines may be used e. g. N-methyl xyl mi N- nitrite is removed with sulfamic acid. The light amberb h d h l glucamine and N.methy1 galactamine. colored tetrazo solution is added slowly to a coupling solution prepared by dissolving 71.7 parts of H acid EXAMPLEZ monosodium salt (0.21 mole) in 220 parts of water containing 24 parts of 10 N NaOH solution, and ad- 24.4 parts (0.1 mole) of o-dianisidine are tetrazotized justing the pH to 9.0 with soda ash. The pH of the as in Example 1 and the light amber colored tetrazo mixture is now adjusted to 7.5 to 8.0 with 10 N NaOH, solution is neutralized with a cold sodium carbonate soand the mass is stirred for approximately 18 hours at lution. A solution of H acid sodium salt is prepared 0 to 5 C. After heating to 60 C. for 30 min., the by dissolving 35.8 parts (0.105 mole) of the monosodium disazo dye is precipitated by adding salt (25 grams of salt of this acid in 200 parts of water containing 16 parts NaCl per 100 cc. of the reaction mixture) and filtered. of a 10 N NaOH solution, and soda ash is added to A disazo dye of the following structure is obtained. bring the pH of this solution to 10.0. The alkaline H- HzN OH C1130 I O C H3 H0 NH:

N=N N=N NaOrs SOaNfl NaOaS SOaNa Part 2.-Metallization acid solution is added slowly to the tetrazo solution at 0 to 5 C. until an excess of. H acid and no excess of tetrazo is found by known tests. The blue slurry of the monoazo diazo compound is then added at 0 to 5 C. to a solution of Gamma acid sodium salt, prepared by dissolving 28.7 parts (0.12 mole) of this acid in 240 The filter cake obtained in Part 1 is slurried in 2000 parts of water at 60 C. and treated with a cuprammonium solution prepared from 181 parts of an aqueous 27% ammonia solution and a solution of parts (0.2 mole) of CuSO .5H O in 150 parts of water. 80 parts (0.45 mole) of N-methyl-glucamine are then added, and the Parts of water 16 Parts of 10 NaOH reaction mass is heated at refluxing temperature for 20 35 Solution and adlustmg thfi P to Wlth sodfum hours, The coppred dye is isolated by adding sodium bonate. The pH of the mixed mass 15 then ad usted to chloride (25 grams per'100 cc.) and filtering. The filter with Sodium carbonate Solutlon, and 240 PaItS of cake is pressed out and dried at 75 C. to yield 200 part pyridine are added. The coupling mass is stirred for 18 of dye. The copper complex obtained has the formula: hours at 0 to 5 C., heated to for 30 min., then X X J. L EN 0 I o o I o r m,

NaO S SOsNa NaOgS SOsNa wherein X represents: treated with 550 parts of sodium chloride and filtered. CH3 An unsymmetrical, disazo dye of the following structure is obtained. NHCH'.-(OHOH)4OH1OH NH: OH 01150 00113 Hfi) Nfloas SOaNa NaO=S This product is a bright, direct, greenish blue dye for The metallization step is carried out as in Example 1. cellulosic fibers and exhibits excellent light fastness, even The coppered dye is isolated by salting, using 900 parts when the dyed fibers are after-treated with resins comof sodium chloride and filtering. The well-pressed filter monly employed for crease proofing or calendering. Furcake is dried at C. to yield 200 parts of dye. The thermore, the novel product dyes mixed fibers of nylon copper complex obtained has the formula X X J, l

NH: 0 I I 0 V o o =N-O N=N N,

NaOtS S OgN'a NaOzS lose fibers.

This product is a direct, greenish blue dye for cellulosic fibers and exhibits excellent light fastness, even if the dyed fiber is after-treated with resins. It dyes The coppering of the disazo dye is carried out as 1 described in Example 2. The coppered dye is isolated mixed fibers of nylon and cotton or nylon and viscose rayon without staining of the nylon fiber.

EXAMPLE 3 In Example 2, the H acid solution isreplaced by a solution of Violet acid sodium salt, prepared by dissolving 32.5 parts of this acid (0.107 mole) in 200 parts of water, 20 parts of 10 N NaOH solution and adjusting the pH to 10 with sodium carbonate. Instead of the Gamma acid sodium saltlsolution a solution of H acid sodium salt is used which is prepared by dissolving 38.3 parts of the mono-sodium salt of this acid (0.112 mole) in 180 parts of water and16 parts of 10 N NaOH solution, followed by the addition of sodium carbonate to obtain pH 10. The tetrazo is first coupled to the Violet acid and then to the H acid. The disazo dye of followingstructure is obtained:

OH 01130 OCH: H

by adding parts NaCl for each 100 parts of solution, and the well-pressed filter cake is dried at 75 C.

The product is a direct bluish gray dye for cellulosic fibers and exhibits excellent light fastness even when the dyed fiber is after-treated with resins. It dyes mixed fibers of nylon and cotton or rayon without staining of the nylon.

(b) The Gamma acid in part (a) of this example is replaced by an equivalent amount of RR acid. The coppered dye obtained is a direct bluish gray dye for cellulosic fibers and exhibits similar properties as the product obtained in part (a).

EXAMPLE 5 (a) Tetrazotized o-dianisidine is coupled to H acid as described in Example 2, and the blue slurry of the' monoazo diazo compound is then added at 0-5 C. to a solution of l-naphthol-S-sulfonic acid, prepared by dissolving 26.8 parts (0.12 mole) of this acid in 200 parts of water and 16 parts of 10 N NaOH. The pH of the solution is then adjusted to 10.0 with sodium carbonate.

NaOaS- S OaNB Naoas S OgNa The disazo dye is coppered and isolated as in Example The coupling mass is stirred for 18 hrs. at 0-5 C.,

1. After drying the filter cake in a 75 oven, parts of coppered dye are obtained, the structure of which is believed to be:

x I x wherein X is:

The coppered dye dyes cellulose fibers in greenish blue shades which possess excellent light fastness even after resin-treatment. Nylon is not stained by the dye when the latter is applied to a mixture of nylon and cellu- EXAMPLE 4 (a) 24.4 parts (0.1 mole) of o-dianisidine are tetrazoitized as in Example 1 and the light amber colored tetraazo solution is neutralized with cold sodium carbonate solution. A solution of RR acid sodium salt is prepared by dissolving 32.8 parts (0.103 mole) of this acid'in 200 parts of water, 24 parts of a 10 N NaOH solution, and soda ash is added to bring the pH of this solution to 10.0. The alkaline RR acid solution is added slowly to the tetraazo solution at 0-5" C. until an excess of RR acid and no excess tetraazo is found by known tests. The slurry of the monoazo diazo compound is then added at 05 C. to a solution of Gamma acid and the'coupling carried out as described in Example 2. The disazo-dye is isolated by adding 25 parts NaCl for each l00parts of solution.

heated to 60 C. for 30 min., then 20 parts NaCl are added per 100 parts of solution to precipitate the dye which is filtered oif.

0 IITH:

Na 0 s S S 0 aNa The metallization step iscarried out as described in Example 2. The well-pressed filter cake is dried at C. giving an excellent yield of dye. The copper complex obtained is a direct greenish blue dye for cellulosic fibers and exhibits excellent light fastness even after the dyed fiber is treated with resins. It dyes mixed fibers of nylon and cotton or rayon without staining of the nylon fiber.

(b) The l-naphthol-S-sulfonic acid in part (a) of this example is replaced by an equivalent amount of R-salt or Epsilon acid. The coppered dyes obtained are direct blue dyes for cellulosic fibers and exhibit similar properties as the product described in part (a) of this example.

(c) The l-naphthol-S-sulfonic acid in part (a) of this example is replaced by an equivalent amount of the sodium salt of Schaefiers acid. The coppered dye obtained from this unsymmetrical disazo compound is a blue direct dye which shows excellent light fastness on cellulosic fibers even after resin treatments.

, EXAMPLE 6 pyrazolone. The coppered dye obtained from this unsymmetricaldisazo dye has the following structure:

X X l t Cu Cu\ NHi o I o o I o NaOaS SOaNa wherein X designates:

CH3 Nn onrwnomronzon The above copper complex is a bluish gray direct dye which shows excellent li'ght'fastness in cellulosic fibers even after resin treatments. Nylon is not stained in mixture with cotton and viscose rayon by this dye.

(b) The procedure is the same as in Example 5(a), except that the l-naphthol-S-sulfonic acid is replaced by an equivalent amount of 1-(6,8-disulfo-l-naphthyl)-3- methyl-S-pyrazolone. The coppering is then carried out as in Example 2. A product having similar properties to that obtained in part (a) of this example is obtained.

EXAMPLE 7 Part (w).Prepwrati0n of N-ethyl H-acid 97 parts of H-acid monosodium salt are slurried in 600 parts of water and dissolved by addition of 20.7 parts of N sodium hydroxide. After adding 47.7 parts of sodium acetate trihydrate the solution is heated to 85 C. and 51 parts of diethyl sulfate are added. After agitation at 85 C. for minutes the solution of ethyl H-acid is cooled and adjusted first to pH 8 (by adding 8 parts of sodium hydroxide and 9 parts of 28% aqueous ammonia) and then to pH 10 (by the aid of soda ash).

Pa rt (b).Preparati0n of the color 24.4 parts of o-di'anisidine are tetrazotized following the method of Example 1. The light amber colored tetrazo solution is neutralized with a cold sodium carbonate solution and then added to the solution of N-ethyl H-acid prepared above.

The coupling solution thus obtained is stirred minutes at 3 C., 5.6 parts of 10 N sodium hydroxide are added and the solution is stirred overnight at 3 C. The

solution is then heated to 85 C., the dye is precipitated by the addition of sodium chloride (8% by volume) and is filtered.

The wet filter cake is dissolved in 1250 parts water at C. and treated with a cuprammonium solution prepared from 56 parts of CuSO .5H O, 205 parts of 28% aqueous ammonia and 200 parts water. After adding 80 parts of methyl glucamine the whole is refluxed for 24 hours, cooled to C., and 385 parts of salt are added. After filtration the wet cake is Washed with 25% salt solution until the filtrate becomes colorless. The filter cake is then dried. One obtains an excellent yield of the following dye:

X X -L 1 Cu Cu CzHsIITH o I o 0 I o NaOsS- SOSNa N803S wherein X is:

E NHCHKCHOHMOHZOH This product dyes cellulosic fibers a greenish blue shade which is greener than that obtained by the dye of Example 1, and in other properties compares favorably with the latter.

EXAMPLE 8 A tetrazotized o-dianisidine solution was prepared as in Example 1 and neutralized with cold sodium carbonate solution then coupled to a solution of K acid (8-aminol-naphthol-3,S-disulfonic acid) prepared by dissolving 76.6 parts (0.24 mole) of this acid in 440 parts of water containing 40 parts of 10 N sodium hydroxide solution and adjusting the pH to 10.0 with sodium carbonate. The coupling procedure itself and the isolation of the disazo dye followed the teachings given in Example 1. The disazo dye was coppered as in Example 1, and the well pressed filter cake of the copper complex was dried at 75 C. An excellent yield of the metal complex was obtained.

The latter is a greenish blue direct dye showing ex cellent light fastness on cellulosic fibers even after resin treatments. This dye does not stain nylon in mixture with cotton or viscose rayon.

The advantages of this invention will now be readily apparent. In addition to the improved light-fastness and other good qualifies mentioned above, most of the dyes obtained according to this invention possess greater brightness than the corresponding dyes coppered in the presence of, say, triethanolamine. This quality is of particular practical interest in connection with those dyes which are of greenish blue shade.

The compounds of this invention are also obtained in an exceptionally high state of purity, as can be readily demonstrated by chromatographic tests.

Finally, when the novel colors of this invention finally fade under prolonged exposure to light, they fade ontone; that is, there is no shift in shade between the faded portion and the unexposed portion. This is a significant advantage over, for example, the triethanolamine counterparts of these colors, which fade considerably off shade.

We claim as our invention:

1. A metallized disazo dye of the formula wherein X is a molecule of an amino-sugar coordinated with the Cu-atorns, R O is the radical of an amino-1- naphthol disulfonic acid to which the azo bridge is at- SOaNa tached in the 2-position, 0-R is the radical of a sulfonated coupling component of the group consisting of naphthol monoand disulfonic acids, amino-naphthol monoand disulfonic acids and monoand disulfonated aryl-methyl-pyrazolones, and the azo bridge is attached to the radical R in position ortho to the O-atom, said amino-sugar being a compound of the formula wherein x is an integer not less than 3 and not greater than 4, while R is a member of the group consisting of hydrogen, methyl, ethyl and betahydroxyethyl.

2. A metallized disazo dye as in claim 1, wherein R O is the radical of H-acid.

3. A metallized disazo dye as in claim 1, wherein R O is the radical of N-ethyl I-I-acid.

4. A metallized disazo dye as in claim 1, wherein R O and O-R are both radicals of H-acid.

5. A metallized disazo dye as in claim 1, wherein R -O is the radical of RR-acid.

6. A process of producing a metallized disazo dye of good brightness and light-fastness, which comprises treating jointly with an aqueous cuprammonium solution and an amino-sugar a disazo dye of the formula OAlk OAlk H I OH wherein Alk is an alkyl radical of 1 to 2 C-atoms, R OH is the radical of an amino-l-naphthol disulfonic acid to which the azo bridge is attached in 2-position, While R OH is the radical of a sulfonated coupling component selected from the group consisting of naphthol monoand disulfonic acids, amino-naphthol monoand disulfonic acids, and monoand disulfonated aryl-methyl-pyrazolones, the azo bridge being attached to the radical R in position ortho to the O-atom, and the treatment being carried out at a temperature between and C., until the alkyl radicals have been eliminated and replaced by Cu atoms, said amino-sugar being a compound of the formula CH OH(CHOH),,CH NHR, wherein x is an integernot less than 3 and not greater than 4, while R is a member of the group consisting of hydrogen, methyl, ethyl and betahydroxyethyl.

7. A process as in claim 6, the quantity of the amino sugar employed being about 4 moles per mole of the disazo compound.

References Cited in the file of this patent UNITED STATES PATENTS 1,989,569 Straub et al. Jan. 29, 1935 2,064,332 Zwilgmeyer Dec. 15, 1936 2,203,196 Hanhart June 4, 1940 2,536,957 Riat et al. Jan. 2, 1951 

1. A METALLIZED DISAZO DYE OF THE FORMULA 